[Wien] Correct band gap value

[Muhammad Sajjad]

Here is the structure with 2% tensile strain.
SILICON

F   LATTICE,NONEQUIV.ATOMS:  1

MODE OF CALC=RELA unit=ang

 10.511739 10.204090 10.204090 90.000000 90.000000 90.000000

ATOM  -1: X=0.12500000 Y=0.12500000 Z=0.12500000
          MULT= 2          ISPLIT=-2
      -1: X=0.87500000 Y=0.87500000 Z=0.87500000
Si         NPT=  781  R0=0.00010000 RMT=    2.2200   Z: 14.0

LOCAL ROT MATRIX:    0.0000000 0.0000000 1.0000000
                     1.0000000 0.0000000 0.0000000
                     0.0000000 1.0000000 0.0000000
  16      NUMBER OF SYMMETRY OPERATIONS

On Thu, Dec 10, 2015 at 12:05 PM, Muhammad Sajjad <sajjadpu at gmail.com>
wrote:

> It looks same (in shape). I selected lattice type F and applied strain.
> Only symmetry operations reduce to 16 from 48 (for bulk Si). Also I kept
> the volume constant for every value of strain.
>
> On Thu, Dec 10, 2015 at 11:29 AM, Fecher, Gerhard <fecher at uni-mainz.de>
> wrote:
>
>> Did you check how the Brillouin zone looks like in the tetragonal case
>> after you applied the strain ?
>> Is your k-path that you used for the xmgrace plot the one that you like
>> to have to find the correct gap ?
>>
>> Ciao
>> Gerhard
>>
>> DEEP THOUGHT in D. Adams; Hitchhikers Guide to the Galaxy:
>> "I think the problem, to be quite honest with you,
>> is that you have never actually known what the question is."
>>
>> ====================================
>> Dr. Gerhard H. Fecher
>> Institut of Inorganic and Analytical Chemistry
>> Johannes Gutenberg - University
>> 55099 Mainz
>> and
>> Max Planck Institute for Chemical Physics of Solids
>> 01187 Dresden
>> ________________________________________
>> Von: wien-bounces at zeus.theochem.tuwien.ac.at [
>> wien-bounces at zeus.theochem.tuwien.ac.at] im Auftrag von Muhammad Sajjad [
>> sajjadpu at gmail.com]
>> Gesendet: Donnerstag, 10. Dezember 2015 09:19
>> An: A Mailing list for WIEN2k users
>> Betreff: Re: [Wien] Correct band gap value
>>
>> Manually means I opened the band structure in xmgrace then simply clicked
>> on the CBM and the went to the text editor to read the exact lowest value.
>> I am simply using Silicon (with 2% strain) and the plot is along W L G X W.
>>
>> On Thu, Dec 10, 2015 at 10:35 AM, <tran at theochem.tuwien.ac.at<mailto:
>> tran at theochem.tuwien.ac.at>> wrote:
>> What does "manually" mean? If it means band structure plotting, then
>> probably the VBM and/or CBM is not along the path in the Brillouin zone
>> that you chose.
>>
>> F. Tran
>>
>>
>> On Thu, 10 Dec 2015, Muhammad Sajjad wrote:
>>
>> I selected 2000 k-points. grep GAP *.scf gives 0.923 eV while manually I
>> found VBM at 0.0 eV and CBM at 1.10023 eV. So which one should be correct?
>>
>> On Thu, Dec 10, 2015 at 12:20 AM, <tran at theochem.tuwien.ac.at<mailto:
>> tran at theochem.tuwien.ac.at>> wrote:
>>       If your k-mesh is not dense enough such that there is no k-point
>>       at the VBM and/or CBM or close to, then :GAP will be larger than
>>       the band gap from a band structure.
>>
>>       F. Tran
>>
>>       On Wed, 9 Dec 2015, Muhammad Sajjad wrote:
>>
>>             Dear AllDoes the command "grep GAP *.scf" gives
>>             correct band gap value? as when I found the bottom
>>             of conduction band in xmgrace it is higher. (bottom
>>             of CB is
>>             read correctly by opening the plot in xmgrace and
>>             then read the date by editing in text editor).
>>
>>             --
>>             Kind Regards
>>             Muhammad Sajjad
>>             Post Doctoral Fellow
>>             KAUST, KSA.
>>
>>
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>>
>>
>>
>> --
>> Kind Regards
>> Muhammad Sajjad
>> Post Doctoral Fellow
>> KAUST, KSA.
>>
>>
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>>
>>
>>
>> --
>> Kind Regards
>> Muhammad Sajjad
>> Post Doctoral Fellow
>> KAUST, KSA.
>> _______________________________________________
>> Wien mailing list
>> Wien at zeus.theochem.tuwien.ac.at
>> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
>> SEARCH the MAILING-LIST at:
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>>
>
>
>
> --
> Kind Regards
> Muhammad Sajjad
> Post Doctoral Fellow
> KAUST, KSA.
>



-- 
Kind Regards
Muhammad Sajjad
Post Doctoral Fellow
KAUST, KSA.
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